IntroductionRecent detection of γ­ray emission from severalNarrow­line Seyfert 1 galaxies (NLS1s) confirms thepresence of relativistic jets in this puzzling class ofactive galactic nuclei (AGN). Our multiepoch verylong baseline interferometric (VLBI) monitoringcampaign is characterizing the parsec­scale structure,spectral properties, polarization, and kinematics ofthese sources.

These observations are complemented by fast­cadencesingle­dish 15 GHz radio monitoring of all sources andoptical spectral monitoring of J0324+3410 to probe theconnection between the jet, black hole, and accretiondisk.

Jets and NLS1 GalaxiesRelativistic jets are a common feature of radio­loudAGN. These outflows are most dramatically showcasedin blazars, where the jet axis points nearly along our

line of sight. Relativistic effects injets lead to phenomena such as

à Apparent superluminal motionà High brightness temperatures

(TB > 1011 K)à Rapid variabilityà High energy γ-ray emission

(up to TeV)1Jets and radio­loudness in AGN

appear associated with large supermassive black holes,proportionally low accretion rates, and elliptical hostgalaxies.NLS1s are AGN similar to Seyfert 1 galaxies, ex-cept their “broad” emission lines are much narrower.Compared to blazars, NLS1s have smaller black holes(.108 M vs &109 M) and higher accretion rates.See, e.g., Foschini (2012) for details.

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Extended Radio Emission

Figure 1. PreliminaryVLA maps of three NLS1 sources from oursample showing clear extension.

Only a few radio­loud NLS1s with kpc­scale extendedradio structure are known (e.g., Doi et al. 2012). FewNLS1s have been mapped on the ~1" scales thatcorrespond to a few kpc, however. We observed threesources from our sample with the Jansky VLA andfound all to show clear arcsec­scale extended emission.This suggests extended emission may be more commonin NLS1s than was thought. Finding a "parentpopulation" of NLS1s with misaligned radio jets wouldhelp understand how these sources fit into the unifiedAGN model (Berton et al. in prep; Foschini 2013).

Kinematics MonitoringOur VLBA monitoring campaign is underway. Threeepochs have been observed so far.

à Multifrequency observations(5, 8, 15, and 24 GHz)

à Full polarizationà 2 Gbps data rateà 7 epochs over ∼1 year

This provides high sensitivity to parsec-scale struc-ture and polarization, with monitoring duration andcadence suitable for characterizing jet kinematics sim-ilar to those seen in blazars.

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VLBI Imaging5 GHz 8 GHz 15 GHz

J084

9+51

08

5 GHz 8 GHz 15 GHz

J090

2+04

43

Figure 2. Example VLBA maps at 5, 8, and 15 GHz from thefirst epoch of our kinematics monitoring program. About 2/3of our targets show parsec­scale extension in our preliminaryanalysis. J0849+5108 (top) has been detected in gamma rays,while J0902+0443 (bottom) has not.

Single­Dish and OpticalMonitoring

4000 4500 5000 5500 6000 6500Wavelength (Å)

2e-15

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08 Dic 201212 Nov 201213 Oct 201217 Sep 201219 Sep 201209 Ene 201307 Feb 201311 Feb 2013

1H 0323+342

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Days since MJD 56079 (2012 Jun 1)

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Figure 3. OVRO 15 GHzradio light curves for brightand faint examples fromour NLS1 sample.

Figure 4. Recent optical spectra of J0324+3410obtained with the GHAO 2.1 m telescope.

γ ? Source z SOVRO (mJy) Score (mJy)

X J0324+3410 0.061 477 ± 7 395

J0814+5609 0.510 21 ± 2 22

X J0849+5108 0.584 337 ± 3 321

J0902+0443 0.533 79 ± 2 62

X J0948+0022 0.585 327 ± 5 332

J0953+2836 0.659 11 ± 4 22

J1047+4725 0.799 192 ± 3 20

X J1246+0238 0.363 17 ± 2 16

J1435+3131 0.502 10 ± 2 21

J1443+4725 0.705 40 ± 4 22

X J1505+0326 0.408 375 ± 4 347

J1548+3511 0.479 46 ± 4 33

J1629+4007 0.272 31 ± 7 41

X J1644+2619 0.145 97 ± 3 97

X J1722+5654 0.426 11 ± 2 211

Table 1. NLS1 monitoring sample.

Sources detected in γ rays are marked. Score is the preliminary15 GHz VLBA flux density of the unresolved core in the firstepoch, with an uncertainty of roughly 10%. SOVRO is the15 GHz single dish flux density, averaged over one monthcentered on the VLBA epoch. Cases where Score>SOVROprobably result from variability.

Sample SelectionRadio-loud NLS1 targets were selected according tothe following criteria:

à Known to be an NLS1à Radio flux density 30 mJy at highest avail-

able archival frequencyà Declination > 0

This resulted in a sample of 15 NLS1s, 7 of which areknown or suspected γ-ray emitters.

1

Boroson 2002, ApJ, 565, 78Doi et al. 2012, ApJ, 760, 41Foschini 2012, paper 010 in Proceedings of Science conf ID 169Foschini 2013, arXiv:1301.5785Lister et al. 2009, AJ, 137, 3718

AGN jet illustration courtesy of NASA

This work is funded in part by NASA through Fermi GuestInvestigator grant NNX13AO79G. The National RadioAstronomy Observatory is a facility of the National ScienceFoundation operated under cooperative agreement by AssociatedUniversities, Inc. The OVRO 40 m monitoring program issupported in part by NASA grants NNX08AW31G andNNX11A043G, and NSF grants AST­0808050 and AST­1109911. This research has made use of the NASA/IPACExtragalactic Database (NED) which is operated by the JetPropulsion Laboratory, California Institute of Technology, undercontract with the National Aeronautics and Space Administration.

1Purdue University, 2INAF, Brera (Italy), 3MPIfR, Bonn (Germany), 4Denison University, 5University of Würzburg (Germany),6Aalto University/Metsähovi, 7Caltech, 8University of Cologne (Germany), 9INAOE, Puebla (Mexico)

Joseph L. Richards1, Matthew L. Lister1, Luigi Foschini2, Tuomas Savolainen3, Daniel C. Homan4,Matthias Kadler5, Talvikki Hovatta6, Anthony C. S. Readhead7,

Tigran Arshakian8, Vahram Chavushyan9

The Parsec­scale Structure and Kinematics ofRadio­Loud Narrow­Line Seyfert 1 Galaxies

References

Acknowledgements